Wireless Technology Terms Glossary and Dictionary [E-G]

E.214
E.214 is a telephone numbering plan used for delivering mobility management related messages in GSM networks. The E.214 number derived from the IMSI E.214 numbers are composed of two parts. The first, the E.164 part, is made up of a country code followed by the network code. The second part of the number is made from the MSIN part of the IMSI which identifies an individual subscriber. For more details on the derivation of the E.214 number from the IMSI, see the article about the IMSI.

EA: Economic Area
Economic Area (EA) is a geographic area over which a WCS operator is licensed to provide service. EAs are a group of counties in metropolitan areas having common financial, commercial and economic ties and were first used to license. WCS service in the late '90s. EAs are about the size of a cellular MSA and cross state lines in some instances. EAs are used by the FCC to define areas of economic interest and are grouped into larger areas called REAGs.

E-AGCH: E-DCH Absolute Grant Channel
E-DCH Absolute Grant Channel(E-AGCH) is one of the five Enhanced Dedicated Channels (E-DCH), which provides an absolute power level above the level for the DPDCH (associated with a DCH) that the UE should adopt. E-AGCH tell a UE how to regulate its transmit power level.

EAP: Extensible Authentication Protocol
Extensible Authentication Protocol (EAP) is a general layer 2 protocol for authentication EAP supports multiple authentication mechanisms. EAP does not select a specific authentication mechanism at Link Control Phase, but rather postpones this until the Authentication Phase. This allows the authenticator to request more information before determining the specific authentication mechanism. This also permits the use of a "back-end" server which actually implements the various mechanisms while the PPP authenticator merely passes through the authentication exchange.

EAPoW: Extensible Authentication Protocol over Wireless
Extensible Authentication Protocol over Wireless (EAPoW) is a term used when EAPoL messages are encapsulated over 802.11 wireless frames.

Eb/N0: Bit Energy-to-Noise Density
Bit Energy-to-Noise Density (Eb/N0) is the ratio of bit energy to noise density. This value is used to specify the lower limit of operation in most digital communications systems and is also used to measure radio channel performance.

EDACS: Enhanced Digital Access Communication System
Enhanced Digital Access Communication System (EDACS) is a radio communications protocol and product family invented in the General Electric Corporation, in the mid-1980s. EDACS was developed in competition with Motorola's Smartnet trunking system. It claimed, and continues to hold, significant market shares.

E-DCH: Enhanced Dedicated Channel
Enhanced Dedicated Channel (E-DCH) is a transport uplink channel used in the 3G technologies (such as HSUPA) to improve capacity and data throughput and reduce the delays in dedicated channels in the uplink. The maximum theoretical uplink data rate that can be achieved is 5.6 Mbps. As with HSDPA, E-DCH relies on improvements implemented both in the PHY and the MAC layer. The definition of the E-DCH introduces five new physical layer channels: E-DPDCH, E-DPCCH, E-AGCH, E-RGCH and E-HICH.

EDGE: Enhanced Data rates for GSM Evolution
Enhanced Data Rates for Global Evolution (EDGE), also known as Enhanced GPRS (EGPRS), is a digital mobile phone technology which acts as a bolt-on enhancement to 2G and 2.5G General Packet Radio Service (GPRS) networks. This technology works in GSM networks. EDGE is a superset to GPRS and can function on any network with GPRS deployed on it, provided the carrier implements the necessary upgrades. EDGE uses the same spectrum allocated for GSM900, GSM1800 and GSM1900 operations.

E-DPCCH: E-DCH Dedicated Physical Control Channel
E-DCH Dedicated Physical Control Channel (E-DPCCH) is one of the five Enhanced Dedicated Channels (E-DCH), which controls channels associated with the E-DPDCH providing information to the Node-B on how to decode the E-DPDCH.

E-DPDCH: E-DCH Dedicated Physical Data Control Channel
E-DCH Dedicated Physical Data Control Channel (E-DPDCH) is one of the five Enhanced Dedicated Channels (E-DCH), which is the physical channel used by E-DCH for the transmission of user data.

EESM: Exponential Effective SIR Mapping
Exponential Effective SIR Mapping (EESM) is a method to estimate demodulator performance in a channel with frequency selective signal and/or noise. In a sense, the EESM is a channel-dependent function that maps power level and MCS level to SINR values in the Additive White Gaussian Noise (AWGN) channel domain. This allows using this mapping along with AWGN assumptions (such as effect of an increase in power, CINR/MCS threshold tables) in order to predict the effect of MCS and boosting modification. The EESM method has been shown to yield an accurate estimation of the AWGN-equivalent SINR for frequency selective channels.

EFR: Enhanced Full Rate
Enhanced Full Rate is a voice coding algorithm applied in PCS-1900 systems (and now in GSM-900 as well, first system installed in Hong Kong).

EGPRS: Enhanced General Packet Radio Service
Enhanced General Packet Radio Service (EGPRS), also known as Enhanced Data Rates for Global Evolution (EDGE), is a digital mobile phone technology. As an enhancement to GPRS, EGPRS improves spectral efficiency and data rates by adding new modulation and coding schemes. EGPRS uses the modulation technique 8PSK (8 Phase Shift Keying) to increase the achievable user data rate.

EGPRS: Enhanced General Packet Radio Service
Enhanced General Packet Radio Service (EGPRS) is an enhancement to GPRS that improves spectral efficiency and data rates by adding new modulation and coding schemes.

E-GSM: Extended Global System for Mobile
EGSM is an extension to the GSM900 spectrum. EGSM spectrum is 880-890 MHz paired with 925-935 MHz, which is just below the original GSM 900 band. EGSM is a small radio frequency band used in Europe to provide added network capacity for GSM 900 networks. The additional 10Mhz provides an additional 50 channels.

EHF: Extremely High Frequency
Extremely High Frequency (EHF) is the RF spectrum between 30 GHz and 300 GHz.

E-HICH: E-DCH HARQ Acknowledgement Indicator Channel
E-DCH HARQ Acknowledgement Indicator Channel (E-HIGH) is one of the five Enhanced Dedicated Channels (E-DCH), which is used by Node-B to send HARQ ACK/NACK messages back to the UE.

EIR: Equipment Identity Register
Equipment Identity Register (EIR) is a database used by GSM and other second generation wireless systems used to identify the customer devices permitted to access the network. A device is usually placed in the EIR once its operation has been certified for the infrastructure in a laboratory or validation facility.

EIRP: Effective Isotropic Radiated Power
Effective Isotropic Radiated Power (EIRP), also known as Equivalent Isotropically Radiated Power, is the amount of power that would have to be emitted by an isotropic antenna (that evenly distributes power in all directions and is a theoretical construct) to produce the peak power density observed in the direction of maximum antenna gain. EIRP can take into account the losses in transmission line and connectors and includes the gain of the antenna. The EIRP is often stated in terms of decibels over a reference power level, that would be the power emitted by an isotropic radiator with an equivalent signal strength. The EIRP allows making comparisons between different emitters regardless of type, size or form. From the EIRP, and with knowledge of a real antenna's gain, it is possible to calculate real power and field strength values.

Electromagnetic Spectrum
Electromagnetic Spectrum refers to the full range of electromagnetic frequencies, which include Radio Frequency (RF).

EMC: Electro Magnetic Compatibility
Electro Magnetic Compatibility (EMC) is the ability of different items of electrical equipment to work together without suffering the effects of interference. Equipment should operate without interfering with broadcast and communications signals and be immune to normal levels of such signals. For a given environment, e.g. on the factory floor, EMC implies that equipment should not generate unacceptable levels of interference which affect the performance of other products designed to operate in an industrial environment. Also, equipment should have sufficient immunity to electrical interference, such that the equipment continues to operate in an acceptable manner.

EMS: Enhanced Messaging Service
Enhanced Messaging Service (EMS) utilizes SMS but adds the ability to incorporate simple graphics, pictures, animations and sound. With this, the user can add an actual emotion to his/her message. Give someone a full birthday wish (with the text, the actual song, and a graphic of a birthday cake).

Encoder
Encoder is a converter used to create a specific addressed message.

EPOC
EPOC, now called Symbian OS, is an operating system optimized for mobile phone/PDA uses. It was developed by Symbian which is a joint company of Psion, Nokia, Ericsson, Motorola and Matsushita (Panasonic). EPOC turns voice-oriented handsets into Mediaphones and Wireless Information Devices. EPOC places a lighter load on the processor compared to present PDA operating systems and thus has the capacity to enhance the multimedia capacity of mobile phones.

Equalization
Equalization is a technique used to compensate for communications channel distortions. This technique is often used in the mobile wireless communications.

E-RGCH: E-DCH Relative Grant Channel
E-DCH Relative Grant Channel(E-RGCH) is one of the five Enhanced Dedicated Channels (E-DCH), which indicates to the UE whether to increase, decrease or keep unchanged the transmit power level of the E-DCH.

ERMES: European radio messaging system
European radio messaging system is a paging system used in Europe and other parts of the world.

Error correction
Error correction is the process of correcting errors in data transmitted over a radio channel using forward error correction (FEC) techniques.

Error probability
Error probability is a computation of the likelihood of an error involving the Probability Density Function (PDF).

Error vector
The error vector is the vector difference between a reference signal and a measured signal and is a complex quantity containing a magnitude and phase component.

ertPS: Extended Real-Time Polling Service
Extended Real-Time Polling Service (ertPS) is one of the five QOS service types defined in the IEEE 802.16 WiMAX. The 802.16 protocol supports five types of QoS -- UGS (Unsolicited grant service), rtPS (Real time polling Service), ertPS (Extended Real-time POLLING SERVICE), nrtPS (Non-real-time polling service and BE (Best effort service). ertPS is a scheduling mechanism that builds on the efficiency of both UGS and rtPS. The ertPS is designed for realtime traffic with variable data rate (such as VOIP service with silence suppression) over the WiMAX network.

ESN: Electronic Serial Number
Electronic Serial Number (ESN) is a unique unchangeable number that is built into the mobile phone and is transmitted by the phone as a means of identifying itself within the system. Each mobile phone is assigned a unique ESN.

ESS: Extended Service Set
Extended Service Set (ESS) is a set of two or more BSSes working together to form a single network.

ESSID: Extended Service Set Identifier
Extended Service Set ID (ESSID) is the identifying name of a wireless network -- strictly, it is the identifying name of a wireless access point. It allows one wireless network to be clearly distinguishable from another. ESSID is one type of SSID (the other being BSSID).

ETACS: Extended Total Access Communications System
Extended Total Access Communications System (ETACS or E-TAGS) is the analog mobile phone network developed in the UK and available in Europe and Asia. ETAGS is the Extension of TACS through the allocation of additional radio channels.

E-TAGS: Extended Total Access Communication System
E-TAGS is Extension of the TACS (Total Access Communications System) system through the allocation of additional radio channels.

E-TDMA: Enhanced or exended TDMA
Enhanced or exended TDMA (E-TDMA) is an enhanced version of TDMA which will not only serve cellular, but could provide PCN-like services within current spectrum allocations.

E-UTRA: Evolved-UMTS Terrestrial Radio Access
Evolved-UMTS Terrestrial Radio Access (E-UTRA or EUTRA), also known as UMTS Long Term Evolution (3GPP LTE) or Evolved UMTS Terrestrial Radio Access Network (EUTRAN), is specified in the 3GPP release 8. It is a key 3G
technology to ensure the competitiveness of UMTS and provide a high-data-rate, low-latency and packet-optimized system. Besides peak data rates of 100 Mbps in downlink and 50 Mbps in uplink, a significant increase in spectrum efficiency and capacity as well as a significant latency reduction are planned. Commercial aspects like costs for installing and operating the network form also part of the requirements.

ETSI: European Telecommunications Standard Institute
European Telecommunications Standard Institute (ETSI) is an independent, non-profit organization, whose mission is to produce telecommunications standards for today and for the future. Based in France, ETSI is officially responsible for standardization of Information and Communication Technologies (ICT) within Europe. These technologies include telecommunications, broadcasting and related areas such as intelligent transportation and medical electronics.

EVDO: Evolution Data Only/Evolution Data Optimized
Evolution Data Only/Evolution Data Optimized (EVDO or 1xEV-DO) is a high-speed network protocol used for wireless Internet data communications. The EVDO protocol supports asymmetric communications, allocating a majority of this bandwidth to downloads. EVDO is based on the 1xRTT standard, providing data transmission speeds wirelessly up to 3.1Mbps. It is for always-on mobile packet data and voice for GPRS-enabled cellular phones, networks and handheld devices.

EV-DV: EVolution for Data and Voice
EVolution for Data and Voice (EV-DV, EVDV or 1xEV-DV) is the technology that provides integrated voice and simultaneous high-speed packet data multimedia services at high speeds. 1xEV-DV is backward compatible to IS-95A/B and CDMA2000 1X and enables a simple migration to 1xEV-DV from 1X networks while preserving existing services offered by operators, including voice and data services on the same carrier, and simultaneous voice and data.

EVM: Error Vector Magnitude
Error Vector Magnitude (EVM) is a modulation quality metric widely used in digital RF communications systems. It is the root-mean-square (rms) value of the error vector over time at the instants of symbol clock transitions. Used properly, EVM and related measurements can pinpoint exactly the type of degradations present in a signal and can even help identify their sources.

Eye diagram
Eye diagram is a superposition of segments of a received PAM signal displayed on an oscilloscope or similar instrument. The eye diagram is used to assess impairments in the radio channel.

FACCH: Fast Associated Control Channel
Fast Associated Control Channel (FACCH) is the channel derived by preempting information in a traffic channel. It is used to send handoff and similar messages.

Fading
Fading is the variation in signal strength from its normal value. Fading is normally negative and can be either fast or slow. It is normally characterized by the distribution of fades, Gaussian, Rician, or Rayleigh.

FASS: Fast Access Station Switching
Fast Access Station Switching (FASS), a concept in the WiMAX network, is a method by which an MS can change its access station from frame to frame depending on the station selection mechanism. The access station can be an RS, BS, or MMRBS. The MS refers to transmitting/receiving data to/from one of the active stations (the anchor station) during any given frame.

Fast fading
Fast fading is the short term component associated with multipath propagation. It is influenced by the speed of the mobile terminal and the transmission bandwidth of the signal.

Fast Handoff
Fast Handoff is a way that access points can let authenticated users roam among different access points without losing authentication. Fast handoff also makes voice-over-IP possible. Fast handoff will be made possible with the 802.11f specification.

FAW: Frame Alignment Word
Frame Alignment Word (FAW) is a unique digital word used by codecs to allow them to resynchronize to the framing structure in the event of errors.

FBSS: Fast Base Station Switching
Fast Base Station Switching (FBSS), defined in the IEEE 802.16-2005 (mobile WiMAX) network, is a method to allow switching between any type of access stations (like RS, BS, or MMR-BS). Switching can occur between the same type or different types of access stations.

FCC: Federal Communications Commission
Federal Communications Commission (FCC) is the regulatory body governing communications technologies in the US. established by the Communications Act of 1934, as amended, and regulates interstate communications (wire, radio, telephone, telegraph and telecommunications) originating in the United States.

FCCH: Frequency Correction Channel
Frequency Correction Channel(FCCH) is the logical channel in GSM systems used to transmit a frequency correction data burst of all "zeros". The resulting frequency shift seen by the mobile is then used for frequency correction.

FCH: Frame Control Header
Frame Control Header (FCH) is a field in the IEEE802.16-2004 WIMAX protocol. The FCH specifies the burst profile and the length of one or more DL bursts that immediately follow the FCH.

FDCCH: Forward Digital Control CHannel
Forward Digital Control Channel (FDDCH), defined in the IS-136, provides cellular standards for TDMA-based networks. FDCCH includes all downstream signalling and control information from cell site to user equipment. FDCCH works together with RDCCH (Reverse Digital Control CHannel) which is for the upstream signaling and controling information. FDCCH can be divided into a few logic channels such as BCCH, SCF and SPACH.

FDD: Frequency Division Duplex
Frequency Division Duplex (FDD), used in cellular communication systems such as GSM, is a radio technology using a paired spectrum.

FDM: Frequency Division Multiplex
Frequency Division Multiplexing (FDM) is a technique by which the carrier bandwidth is divided into sub-channels of different frequency widths -- each carrying a signal at the same time in parallel. Each channel is 30 kHz. All the signals may be amplified, conducted, translated in frequency and routed toward a destination as a single signal, resulting in economies which are the motivation for multiplexing. Receivers at the receiving end separates the multiplexed signals by means of frequency passing or rejecting filters, and demodulates the results individually, each in the manner appropriate for the modulation scheme used for that band or group.

FDMA: Frequency Division Multiple Access
Frequency Division Multiple Access (FDMA) is a method of allowing multiple users to share the radio frequency spectrum by assigning each active user an individual frequency channel. In this practice, users are dynamically allocated a group of frequencies so that the apparent availability is greater than the number of channels.

FFT: Fast Fourier Transform
Fast Fourier Transform (FFT) is an efficient algorithm to compute the discrete Fourier transform (DFT) and its inverse. FFTs are of great importance to a wide variety of applications, from digital signal processing to solving partial differential equations to algorithms for quickly multiplying large integers.

FGD: Feature Group D
Feature Group D (FGD) is a local exchange carrier network service that, among other things, lets public-safety dispatch offices receive a 10-digit data stream, including the full call-back number, alongside wireless 911 calls. FGD is offered as a way by which wireless carriers can meet FCC-enhanced 911 rules and dispatch offices can overcome their current bandwidth limits. This access group is associated with equal access arrangements which allow the end user to have the same dialing plan (1 plus the telephone number) to reach any predetermined long distance phone companies of their choice.

Feature Group D
Feature Group D is a local exchange carrier network service that, among other things, lets public-safety dispatch offices receive a 10-digit data stream, including the full call-back number, alongside wireless 911 calls. Offered as a way by which wireless carriers can meet FCC enhanced 911 rules and dispatch offices can overcome their current bandwidth limits.

FEC: Forward Error Correction
Forward Error Correction (FEC) is a method of increasing the reliability of data communication. In one-way communication channels, a receiver does not have the option to request a re-transmission if an error was detected. Forward Error Correction is a method of sending redundant information with the data in order to allow the receiver to reconstruct the data if there was an error in transmission.

FER: Frame Erasure/Error Rate
Frame Erasure/Error Rate is a measure of the number of frames of data that contained errors and could not be processed. FER is usually expressed as a percentage or exponent.

FH: Frequency Hopping
Frequency Hopping (FH) is a periodic changing of frequency or frequency set associated with transmission. It is a sequence of modulated pulses having a pseudorandom selection of carrier frequencies.

FH-CDMA: Frequency Hopping - Code division multiple access
Frequency hopping - code division multiple access (FH-CDMA) is one of two basic modulation techniques used in spread spectrum signal transmission for CDMA-based wireless systems. It is the repeated switching of frequencies during radio transmission, often to minimize the effectiveness of the unauthorized interception or jamming of telecommunications.

FHSS: Frequency Hopped Spread Spectrum
Frequency Hopped Spread Spectrum (FHSS) is a spread-spectrum method of transmitting signals by rapidly switching a carrier among many frequency channels, using a pseudorandom sequence known to both transmitter and receiver. It is used in WLAN 802.11 physical layer.

FIRFinite Impulse Response
Finite Impulse Response (FIR) is a technique used to characterize electrical circuits and‚ networks in the time domain.

Fixed WiMax
Fixed WiMax refers to the fixed wireless broadband services as defined by the IEEE 802.16d (also known as IEEE 802.16-2004). IEEE 802.16d product profile utilizes the OFDM 256-FFT (Fast Fourier Transform) system profile. The Fixed WiMAX 802.16-2004 standard supports both time division duplex (TDD) and frequency division duplex (FDD) services -- the latter of which delivers full duplex transmission on the same signal if desired. The mobility features of WiMax are defined in IEEE 802.16e (or 802.16-2005).

Fixed Wireless
Fixed wireless refers to the over-the-air transmission of information to and from systems and end-user equipment that are stationary, rather than mobile. Operators of fixed wireless networks potentially can offer broadband services without having to lay expensive cable systems or deal with the complexities of mobility management.

Flat fading
Flat fading is a type of fading in a communications channel that attenuates or fades all frequencies in the channel in the same amount.

FLEX
FLEX is the Motorola's flexible high-speed paging coding scheme that gives carriers more capacity on their networks and faster transmission time. FLEX also refers to the FLEX family of protocols: FLEX, InFLEXion and ReFLEX.

FM: Frequency Modulation
Frequency Modulation (FM) is a form of angle modulation in which the instantaneous frequency of a sine-wave carrier is caused to depart from the carrier frequency by an amount proportional to the instantaneous value of the modulating wave. In FM, signals of different frequencies represent different data values.

Foliage attenuation
Reductions in signal strength or quality is due to signal absorption by trees or foliage obstructions in the signal's line-of-sight path. For example, 800 MHz systems are seldom deployed in forested areas. Pine needles-nearly the same length as 800 MHz antennas can negatively affect signal reception in that band.

FOMA: Freedom of Mobile Multimedia Access

Freedom of Mobile Multimedia Access (FOMA) is the brand name for the 3G services being offered by Japanese mobile phone operator NTT DoCoMo. FOMA was the world's first W-CDMA 3G service when launched in 2001. FOMA is compatible with standard UMTS, both via the radio link as well as via USIM card exchange, and hence provides several alternative options for global roaming: either with or without change of handset.

Footprint
Footprint in wireless communications refers to geographical areas in which an entity is licensed to broadcast its signal.

Forward Channel
Forward Channel is used by the base station to communicate with a mobile station.

Forward link
In radio communications, a forward link is the link from a fixed location (e.g., a base station) to a mobile user. If the link includes a communications relay satellite, the forward link will consist of both an uplink (base station to satellite) and a downlink (satellite to mobile user).

Frequency
Frequency is the measurement of the number of times that a repeated event occurs per unit time. To calculate the frequency of an event, the number of occurrences of the event within a fixed time interval are counted, and then divided by the length of the time interval.>/p>

Frequency diversity
Frequency diversity is the simultaneous use of multiple frequencies to transmit information. This is a technique used to overcome the effects of multipath fading since the wavelength for different frequencies result in different and uncorrelated fading characteristics.

Frequency reuse
Frequency reuse is a technique of reusing frequencies and channels within a communications system to improve capacity and spectral efficiency. Frequency reuse is one of the fundamental concepts on which commercial wireless systems are based that involves the partitioning of an RF radiating area (cell) into segments of a cell. One segment of the cell uses a frequency that is far enough away from the frequency in the bordering segment that it does not provide interference problems. Frequency re-use in mobile cellular systems means that each cell has a frequency that is far enough away from the frequency in the bordering cell that it does not provide interference problems. The same frequency is used at least two cells apart from each other. This practice enables cellular providers to have many times more customers for a given site license.

Frequency selective fading
Frequency selective fading is a type of signal fading occurring over a small group of frequencies caused by a strong multipath component at those frequencies.

Fresnel Zone
Fresnel Zone is an elliptical area on either side of the straight line of sight that must also be clear for a long-range wireless network to work.

Fringe Area
Fringe Area is the outermost range of a cellular system where cellular signals may be weaker.

FRS: Family Radio Service
Family Radio Service is a very low power, short range two-way radio service in the 460 MHz band.

FRS: Fixed Relay Station
Fixed Relay Station (FRS) refers to a relay station that is permanently installed at a fixed location.

FSKFrequency Shift Keying
Frequency Shift Keying (FSK) is a form of modulation using multiple carrier frequencies to carry the digital information. The most common one is the two-frequency FSK system using the two frequencies to carry the binary ones and zeros.

FSSS: Fast Serving Station Switching
Fast Serving Station Switching (FSSS) refers to the serving station switching with which a Moble Station (MS) can change its serving station from frame to frame depending on the serving station selection mechanism. A serving station can be an RS, BS, or MMR-BS. Fast BS switching (FBSS) was defined in 802.16e, and the terminology is modified to allow switching between any types of serving stations (RS, BS, or MMR-BS). Switching can be either between a same type of serving stations or between different types of serving stations.

Full rate
Full rate refers to voice codecs in a communications system. Most frame formats are designed to accommodate full and half-rate channels, with the intention of implementing half-rate coding as the technology permits to double the capacity of the system. The full-rate codec uses all of the
time-slots available.

Full user mobility
Full user mobility is a wireless classification under which users can access data while in motion, for example, in a car.

FUSC: Fully Used SubChannel
Fully Used SubChannel (FUSC), also known as Fully Used SubCarrier, is a method used in the WiMAX network that uses all the subchannels and employs full-channel diversity by distributing the allocated subcarriers to
subchannels using a permutation mechanism. This mechanism is designed to minimize the probability of hits (probably of using the same physical subcarriers in adjacent cells and sectors) between adjacent sectors/cells by reusing subcarriers while frequency diversity minimizes the performance degradation due to fast fading characteristics of mobile environments.

FWA: fixed wireless access
Fixed wireless access, also known as wireless local loop, is a wireless system in which office or home users directly connect with the switching center of the telecommunications carrier or the inter-exchange channel to use the system.

Gain
Gain refers to the ratio of the output amplitude of a signal to the input amplitude of a signal. This ratio typically is expressed in dBs. The higher the gain, the better the antenna receives or transmits but also the more noise it includes.

GAN: Global Area Network
Global Area Network (GAN) is a network that is composed of different interconnected computer networks and covers an unlimited geographical area.

Gaussian channel
Gaussian channel is an RF communications channel having the properties of a wide-band uniform noise spectral density resulting in a random distribution of errors in the channel.

Geosynchronous Orbit
A geosynchronous orbit has the same orbital period as the sidereal rotation period of the Earth. It has a semi-major axis of 42,164 km.

GERAN: GSM (GPRS)/EDGE Radio Access Network
GSM(GPRS)/EDGE Radio Access Network (GERAN) is the name given to the 3GPP standards for GSM(GPRS)/EDGE radio access, which has been specified to connect the A, Gb and Iu interfaces to the CN (Core Network). The architecture allows two BSS (Base Station Subsystem) to be connected to each other.

GGSN: Gateway GPRS Support Node
Gateway GPRS Support Node (GGSN) is a gateway from a cellular network to an IP network that allows mobile cell phone users to access the public data network (PDN) or specified private IP networks. The GPRS Core Network is the centralised part of the GPRS system and also provides support for UMTS-based 3G networks.

GHz: GigaHertz
GigaHertz (GHz) is one billion hertz, which is a measurement of frequency.

Gi interface
Gi interface is the reference point between a GPRS network and an external packet data network.

GIS: geographic information system
Geographical Information System (GIS) refers to a computer system capable of capturing, storing, analyzing, and displaying geographically referenced information, that is, data identified according to location. Practitioners also define a GIS as including the procedures, operating personnel, and spatial data that go into the system.

GLONASS: global navigation system
Global navigation system (GLONASS) is a Russian satellite location technology similar to global positioning system.

GMM/SM: GPRS Mobility Management / Session Management
GPRS Mobility Management/Session Management (GMM/SM) protocol supports mobility management functionality of a mobile such as GPRS attach, GPRS detach, security, routing area update, location update. The main function of the Session Management (SM) layer is to support PDP context handling of the user terminal. SM comprises of procedures for the PDP context activation, deactivation and modification. The GMM layer uses the services of the Radio Access Network Application Protocol (RANAP) over the Iu interface to provide these services.

GMM: GPRS Mobility Management
GPRS Mobility Management (GMM) is a GPRS signaling protocol that handles mobility issues such as roaming, authentication, and selection of encryption algorithms. GPRS Mobility Management, together with Session Management (GMM/SM) protocol, supports the mobility of user terminal so that the SGSN can know the location of a mobile station (MS) at any time and to activate, modify and deactivate the PDP sessions required by the MS for the user data transfer.

Gn Interface
Gn Interface is the interface between GSNs within the same PLMN in a GPRS network. GPRS Tunneling Protocol (GTP) is a protocol defined on both the Gp and Gn interfaces between GSNs in a GPRS network.

GOS: Grade of Service
Grade of Service (GOS) is a measure of the success a subscriber is expected to have in accessing a network to complete a call. The grade of service is usually expressed as percentage of calls attempted by the subscriber during the busy-hour that are blocked due to insufficient network resources.

Gp Interface
Gp Interface is the Interface between GSNs within different PLMNs in a GPRS network. GPRS Tunneling Protocol (GTP) is a protocol defined on both the Gp and Gn interfaces between GSNs in a GPRS network.

GPRS: General Packet Radio Service

General Packet Radio Service (GPRS) technology runs at speeds of up to 115Kbit/sec., compared with the 9.6Kbit/sec. of older GSM systems. It enables high-speed wireless Internet and other communications such as e-mail, games and applications. It supports a wide range of bandwidths and is an efficient use of limited bandwidth. It's particularly suited for sending and receiving small amounts of data, such as e-mail and Web browsing, as well as large volumes of data.

GPS: Global Positioning System
The Global Positioning System (GPS) is a "constellation" of 24 satellites that orbit the Earth at a height of 10,900 miles, making it possible for people using ground receivers to determine their geographic location within 10 to 100 meters. The satellites use simple mathematical calculations to broadcast information that is translated as longitude, latitude and altitude by Earth-based receivers.

GPT: GPRS Tunneling Protocol
GPRS Tunneling Protocol (GTP) is a protocol used by the GPRS backbone network for packet switching. GTP is a protocol defined on both the Gn and Gp interfaces between GSNs in a GPRS network.

Ground Station
Ground Station, also called a downlink station, refers to the collection of communications equipment designed to receive signals from (and usually transmit signals to) satellites.

GSM 1800
GSM 1800, also known as DCS 1800 or PCN, is a moble network working on a frequency of 1800 MHz. It is used in Europe, Asia-Pacific and Australia.

GSM 1900
GSM 1900, also known as PCS 1900, is a mobile network working on a frequency of 1900 MHz. It is used in the US and Canada and is scheduled for parts of Latin America and Africa.

GSM 900
GSM 900, or just GSM, is the world's most widely used digital network -- now operating in over 100 countries around the world, particularly in Europe and Asia Pacific.

GSM plus
GSM plus is an enhanced version of global system for mobile communications (GSM) technology that will be developed to meet IMT-2000 capabilitiesGSM: Global System for Mobile Communications Global System for Mobile Communications (GSM), origionally known as Groupe Special Mobile, is a digital cellular system defined by ETSI based on TDMA
narrowband technology. GSM allows up to eight simultaneous communications on the same frequency. GSM is widely deployed in Europe and some Asian Countries, competing with CDMA which was developed by Qualcomm and deployed mainly in the US.

GSM-R: GSM for Railway networks
Global system for mobile communications for Railway networks (GSM-R) uses standard base station and switching infrastructure to provide fast data transmission for railwaysGSN: GPRS Support Nodes GPRS Support Node (GSN) is a network node which supports the use of GPRS in the GSM core network. All GSNs should have a Gn interface and support the GPRS tunnelling protocol. There are two key variants of the GSN: the GGSN and the SGSN.

GTP: GPRS Tunnelling Protocol
GPRS Tunnelling Protocol (GTP) allows end users of a GSM or UMTS network to move from place to place whilst continuing to connect to the internet as if from one location at the GGSN. It does this by carrying the subscriber's data from the subscriber's current SGSN to the GGSN which is handling the subscriber's session. GTP version zero supports both signalling and user data under one generic header. It can be used with UDP (User Datagram Protocol) or TCP (Transmission Control Protocol) on the registered port 3386. GTP version one is used only on UDP. The control plane protocol GTP-C (Control) using registered port 2123 and the user plane protocol GTP-U (User) using registered port 2152.

GTP Tunnel
GTP Tunnel is used to communicate between an external packet data network and a mobile station in a GPRS network. A GTP tunnel is referenced by an identifier called a TID and is defined by two associated PDP contexts residing in different GSNs. A tunnel is created whenever an SGSN sends a Create PDP Context Request in a GPRS network.

Guard Band
Guard Band is a set of frequencies or band-width used to prevent adjacent systems from interfering with each other. Guard bands are typically used between different types of systems at the edges of the frequency allocations.

GWEN: Ground Wave Emergency Network
Ground Wave Emergency Network (GWEN) is a communications system that the US military constructs. It operates in a very-low-frequency range, with transmissions between 150 and 175 kHz. This range was selected because its signals travel by means of waves that have a tendency to hug the ground rather than by radiating into the atmosphere. This signal drops off sharply with distance -- a single GWEN stations transmits in a 360 circle to a distance of 250 to 300 miles. The entire GWEN system consists of approximately 300 such stations spread across the United States, each with a tower 300-500 feet high. The stations are from 200 to 250 miles apart, so that a signal can go from coast to coast or from one station to another. When the system is completed around 1993, the entire civilian population of the United States will be exposed to the GWEN Transmissions